Appearing on The AM Show on Tuesday, Ms Ardern agreed there was a problem.

"I think there's an imbalance in our boards, I think perhaps if you just saw the number everyone would agree with that," she says

"When you've got 81 percent of your boards made up by a particular demographic - then obviously we have an imbalance."

Ms Genter, a Green Party MP, argues these old white men need to know when to leave and make way for the next generation.

"The simple mathematical reality is that if we're to have more diversity on boards then some current members will to have to step aside to let new talent rise up," she says.

"There are a number of male directors who have been champions for this kind of change, who are helping to recruit young people and women for leadership roles. Part of leadership is knowing when to step aside and let the new talent come through."

But Ms Ardern doesn't expect company directors to leave before they think it's necessary.

"There's talent on our boards as well. What we're trying to do is make sure that we're able to keep that renewal and bring in that balance," she told host Duncan Garner.

"How that happens, whether it's through people naturally resigning, that's an easy way to do it.

"Do I expect people to stand down before they're ready? No I don't. But I do absolutely acknowledge what she's saying."

Ms Genter's comments have caused widespread controversy. Former Conservative Party board member John Stringer has lodged a formal complaint with the Human Rights Commission.

He says he is "tired of the continual denigration and stereotyping of European males of older ages in politics and the media".

"We have become the whipping boys, which is somehow justified because we are seen to be in power - well she is in power... I think Julie Anne Genter is a woman of power and influence."

National Party leader Simon Bridges told the AM Show on Monday he disagreed with the minister's comments, labelling them "virtue signalling".

"It's pointless stuff. If you look at the reality of it, their Cabinet has fewer women than ours did, their front bench has fewer women than ours did," he says.